1. Field of the Invention
The present invention relates to a golf ball, and more particularly, to the golf ball having a superior flight performance which is obtained by improving the method for processing dimples to be formed on the surface thereof.
2. Description of the Related Arts
Normally, 280 to 540 dimples are formed on the surface of the golf ball to improve the aerodynamic characteristic thereof and as such increase the flight distance thereof. Various proposals of dimple arrangement and dimple configuration have been made to improve the fight performance of the golf ball.
In order to accomplish non-orientation performance and stabilize the separation point of the golf ball, the present applicant filed Japanese Patent Laid-Open Publication No. 62-192181 which describes the method for reducing the number of great circles which do not intersect dimples based on the idea that the golf ball has no great circles on the surface thereof.
Normally, the golf ball is molded by a pair of upper and lower semispherical molds having a pattern of many dimples. Therefore, a burr is formed on the seam of the golf ball corresponding to the connecting portion of the upper and lower molds. Dimples are not formed on the connecting portion of the pair of the molds because the burr is removed from the golf ball by polishing after a material is molded into the golf ball by the pair of the molds. Therefore, dimples are not formed on the seam. As such, it is unavoidable that the golf ball manufactured by the pair of the molds has a great circle on the seam which does not intersect dimples. Therefore, it is impossible to eliminate the great circle formed on the surface of the golf ball so long as it is manufactured by the pair of semispherical molds.
In order to overcome the above problem, Japanese Patent Laid-Open Publication No. 64-8983 discloses a technique for forming dimples by processing the outer layer of the golf ball with a cutting tool so that it has no great circles.
It is necessary to form 280 to 540 dimples on the surface of the golf ball. Therefore, this technique has a disadvantage in view of manufacturing process and accuracy. That is, in case that all dimples are formed with the cutting tool individually, it takes a lot of time to form dimples, which leads to an increase in manufacturing cost. That is, it is almost impossible to mass produce golf balls. Further, it is inevitable that dimple configurations and the distance between adjacent dimples become nonuniform. Accordingly, golf balls having the same dimple specification have a nonuniform flight performance.